Routing Protocols

Due to recent concerns over the impending depletion of the current pool of Internet addresses and the desire to provide additional functionality for modern devices, an upgrade of the current version of the Internet Protocol (IP), called IPv4, is has been standardized. This new version, called IP version 6 (IPv6), resolves unanticipated IPv4 design issues and takes the Internet into the 21st Century. Transitioning networks to the next version of the Internet Protocols could be a bargain, according to a recent study by RTI Inter-national of Research Triangle Park, N.C. The report, done at the request of the National Institute of Standards and Technology, estimated the costs in the US at $25.4 billion over 25 years, most of that in increased labor costs. "Although these cost estimates seem large, they are actually small relative to the overall expected expenditures on IT hardware and software, and even smaller relative to the expected value of potential market applications," the report concluded. Costs will be incurred largely because IPv6 is expected to coexist with IPv4 for the foreseeable future, and administrators will have to manage both network types. "As a result, labor costs will constitute the majority of the cost of upgrading to IPv6 for users, and training will constitute the majority of these additional labor costs," RTI said.

IPv6 is intended to provide more addresses for networked devices, allowing, for example, each cell phone and mobile electronic device to have its own address. IPv4 supports 4.3Ч109 (4.3 billion) addresses, which is inadequate for giving even one address to every living person, much less support the burgeoning market for connective devices. IPv6 supports 3.4Ч1038 addresses, or 5Ч1028(50 octillion) for each of the roughly 6.5 billion people alive today. Invented by Steve Deering and Craig Mudge at Xerox PARC, IPv6 was adopted by the Internet Engineering Task Force in 1994, when it was called "IP Next Generation" (IPng). (Incidentally, IPv5 was not a successor to IPv4, but an experimental flow-oriented streaming protocol intended to support video and audio.)

As of December 2005, IPv6 accounts for a tiny percentage of the live addresses in the publicly-accessible Internet, which is still dominated by IPv4. The adoption of IPv6 has been slowed by the introduction of network address translation (NAT), which partially alleviates address exhaustion. The